1. Field of the Invention
The present invention relates to a process and apparatus for mechanically and biologically breaking down the components of used disposable sanitary articles and such single use products which contain human feces and/or urine. These articles include but are not limited to products or portions of products worn by infants and adults as sanitary diapers, pads napkins or sheets and the like. The present process and apparatus is intended for disinfection and reclamation of materials contained in such disposable products. Disease causing bacteria are eliminated while reclaiming the components of such products in a form usable in the remanufacture of like products or as raw materials for other uses or for other manufactured products. In this manner the components of the used disposable sanitary articles are recycled resulting in a significant lessening of resource demand, a significant reduction in environmental pollution and a reduction in solid waste that normally terminates in sanitary land fills.
2. Description of the Prior Art
Disposable sanitary products of the character described, also referred to as "single use" or "one use" human waste collecting or absorbing products, are now in widespread use in this and other countries of the world. These disposable products have in fact become the predominant method for collecting and absorbing human waste from both children and adults when required and have all but replaced cloth diapers. Although in some instances these used, contaminated sanitary items are disposed of by incineration, the more common practice is to deposit them in waste disposal systems which usually terminate in land fills. Since the numbers of such items range in the billions annually in the U.S. alone, the volume of waste material from this source has begun to burden our sanitary land fills. The resulting environmental contamination and pollution from human waste threatens underground water supplies and surface water runoff. Other health problems, due to the bacteria found in human waste, may include disease and infection by direct contact. Incineration, on the other hand, is usually costly and inefficient and itself creates atmospheric pollution.
The primary components of the disposable sanitary products of the type under consideration include cellulose fibers, absorbent granular materials (AGM), plastics and miscellaneous waste materials such as metal fasteners and the like. At present there is no efficient and economically feasible process or apparatus available for mechanically and biologically breaking down these materials. The problem of treating these materials to kill disease causing bacteria such that effluent and wastes are controlled so as to maintain safe discharges in the form of treated water has not been adequately addressed. Likewise disinfection of reclaimed materials and providing for a contamination free processing environment has not been accomplished with known methods and apparatus.
A number of recycling systems have been proposed for reclaiming the valuable wood pulp, cellulose flock absorbent materials and plastics used in the production of single use sanitary products. These efforts have been directed primarily to the reclamation of reusable components of clean waste or production overruns resulting from the original manufacturer of the disposable products. The materials being processed in these systems are unused and uncontaminated and present no pollution problems. The following patents are examples of such processes;
U.S. Pat. No. 4,500,040 Steffens
U.S. Pat. No. 4,305,507 Wittkopf
U.S. Pat. No. 4,303,501 Steffens
U.S. Pat. No. 3,890,220 Anderson
A more recent effort is disclosed in U.S. Pat. No. 4,990,244 to Anderson which is directed to processing contaminated single use sanitary products containing urine and/or feces. The Anderson process utilizes a hot water washing machine with sufficient heat to melt and liquidize the adhesives which bond absorbing materials to the moisture sealing plastic material. These components may then be separated by such means as an oscillating separator and/or screening process. The Anderson process and apparatus is merely a washing and materials separation process and does not concern itself with mechanically and/or biologically breaking down the components of the contaminated composites. No attempt is made to disinfect or otherwise biologically treat the wastes and disease causing bacteria. The Anderson process can be characterized as an open vat process with no provision for control of noxious fumes or contact with contaminated human waste. Open processing of this type of material can itself constitute health hazards for personnel in the immediate vicinity.